Method of making screen pipe



April 6 1926.

R. A. STEPS METHOD OF MAKING CREEN PIPE Filed March 30, 1925 Gwm W [NVEN TOR Patented Apr. 6, 1926.

UNITED STATES BOBERT ALEXANDER S TEPS, OF LOS ANGELES, CALIFORNIA.

METHOD OF MAKING SCREEN PIPE.

Application filed March 30, 1923. Serial No. 628,945.

To all whom it may concern:

Be. it known that 1, ROBERT ALEXANDER STEPS, a citizen of the UnitedStates, resid ing at Los Angeles, in the county of Los Angeles and Stateof California, have invented a new and usefulMethod of Making ScreenPipe, of which the following is aspecification. 1

My present invention relates to an improved modification of the moregeneralinvention shown in my Patents No. 1,207,808 and 1,207,809.

The object of the present invention-is to simplify the manufacture ofscreen pipes of the kind involved, andto increase their screeningcapacity at the same time that the cost of manufacture is reduced.

It is understood that the screen pipes to which this'invention appliesis used in oil or water wells for the purpose of holding the sand andgravel out, while the fluid passes through and is pumped to the surfaceof the earth by proper. pumps installed in the well. Ifthenatural,pressureonthe fluid is suflioiently great the pump may of coursebe dispensed with as the fluid will then rise in thewell under itsownpressure. 7

Screen pipes of this sort are made of heavy steel or iron pipe withsuitable screening apertures formed therein. The pipe comes in sectionsof various lengths, often about 20 ft. each, and from 4 to 16 inches indiameter, and these sections are screwed together to give the requiredlength of screen corresponding with the thickness of the strata in whichthe desired fluid is found.

The tendency of course is for the sand and gravel to come through thescreen with the fluid, but this is undesirable for many reasons, and onthis account care must be eyercised in so forming the screeningapertures that they hold'back the sand effectively without retarding theflow of the liquid.

It is this result which my invention accomplishes very nicely. Thescreening apertures formed in accordance with my invention are narroweron the outside of the pipe than they are on the inside, so that theexternal sands are held out right at the outside surface of the pipe,but if any particles get past the narrower outside portion of the slotthey pass right through the slot without sticking or cloggingtherein, asthe slots which I produce are wider toward the inside than theyaretoward the outside of the pipe where the reeal excluding action of thesand is effected.

Claim for the screen pipe herein described I is made in my copendingapplication No. 59,585, filed September 80, 1925.

For the purpose of increasing the screening capacity without increasingthe cost of manufacture of this kind of screen I have grouped my slotsinto pairs, because by my new method of operation I amnowable to producea pair of slots as easily as a single slot could be produced, so thatthe added screening benefit of the extra slot is obtained without anyincrease in cost; c

The broad steps of this invention are pointed out in the claims. Thesesteps can be performed in various ways, and I will now describe what Iregard as the preferred way or ways. V I

In the accompanying drawings Fig 1 shows a way of carrying out the firststep in my invention, which consists in forming pairs of slots in thepipe preferably with slotting saws mounted on a common arbor. Fig. 2 isa side view indicating the shape of the slotting saws diagrammatically.,Fig. 3' shows a way of carrying out the second step in' my inventionwhereby the slots are formed so as to be narrower toward the outside ofthe pipe than they are at the inside of the pipe. Figure l is a sideview of the tool shown in Fig. 3. Fig. 5 shows another way of carryingout the second step of my invention, and Fig.6 is a side View of thetool shown in Fig. 5. Fig. 7 shows a short piece of the screen pipefinished in accordance with my invention, and Fig. 8 is a transversesection of same.

By mounting the usual slotting saws 1 close together on the common arbor2, Fig. 1, a pair of slots 3 may be out in the wall of the pipe 4, a bar5 separating the slots in the pair. At the end of this first-step in mymethod the side walls of the slots are substantially parallel, and theslots'are as wide on the outside of the pipe as they are on, the insideof the pipe- Figs- 3 and 4r. show a roller 6 adapted to bridge acrosstheipair of slots, the edges '7 of the roller being spaced sufiicientlyapart to rest on the edges of the slots which are fu'rthermost forthalong the length of the slots, and

ll (l as this continues these edges of the slots are pressed toward.each other.

In practice I use pneumatic or: hy-r draulic cylinder for producing therequired pressure on the roll, and in view of the concavity 10 ot' tlierolltlie above operation is very nicely accomplished. In fact, thenumber of strokes back and" forth along the slots, determines the degreeto which th lips are pressed toward each other, and if narrower'slotsare desired. it is merely nec essary to give the roller a few morevstrokes before. the'pressureisreleased.

At the end. oii this rolling'operation the slots are scento be narrowerat the. outside of the pipe thanthey are at the inside This gives theeffective screeningqualities.

which have already been described.

5 and-6 show another. tool 11 in the nature of a chisel", whichinay be.used, in place of. roller. 6. In"tlUSTCaSB'tll6:-(3l11$l' may bestrnckwvith any sort of'afliainm'er on the chisel head .12 and"the-opposite edges of the slot will thus be forced; on pressed towardeach. other.

After completing one pair of slots: the

operation is repeated as often as desired until the entire section ofpipe is thus' in the pipe, in place of longitudinally as I hang: sho vnthem, as my invention is equally applicable Whether the slots runlengthwise of the pipe or otherwise. It is obviously important that theslots in each pair sliould' be comparatively close togethercomparedwit-h. the distance between neighboring paii's of 'slots, asthis gives the increased screening area without correspondinglyweakening the pipe.

I claim.

1-. The method of-makingscreen pipe consisting. in slotting the pipewith pairs of slots, the slots in each pair beingv close togetherxcoinparred with the distance between pairs, and thensimultaneously forcing the edges of: the slots. on the outside of thepipe furthermost from each other in an; pair, toward eachother so as tomake each slot. narrower on the outside of the pipe than. on; the"inside. i

2. The method of making screcnpipe consisting. in" slotting the pipewith pairs of slots, the, slots in each pair being close togethercompared with the distance between pairs, andz'then applying arolleradapted to bridge across 'the edges of the slots furtli'erinost'from each other in any pair, and moving said roller lengthwise of theslots. under pressure sons to force the last said edges of the slotstoward each other to make each slot narrower on the outside Of thepipethan on the ins de.

Signed at Denver, In the county ofDenver and State of Colorado, thisQGthday of March, 1923.

ROBERT ALEXANDER STEPS.

